The present disclosure generally relates to power transmission devices, and, more particularly, to a transmission having a selectively operational torque converter.
Many vehicle automatic transmissions are equipped with a torque converter installed at the input end of the transmission. The torque converter is typically the component directly coupled to an output shaft of the engine. Accordingly, whenever the automatic transmission is operated, the torque converter is rotated. Due to the relative rotation of components in the torque converter, some energy is converted to heat. An energy loss occurs and efficiency of the transmission is reduced by operation of the torque converter. Furthermore, it should be appreciated that conventional transmissions require the torque converter to rotate for every gear ratio provided by the transmission. This rotating inertia of the torque converter reduces the overall efficiency of the drivetrain.
Torque converters may provide a number of desirable features including torque multiplication depending on the relative speed differential between the input to the torque converter and the output. Furthermore, torque converters may allow a transmission to remain in first gear when the vehicle is stopped while also providing a transfer of torque during launch when requested by the vehicle operator. While many of the benefits of using a torque converter in an automatic transmission may still exist, it may be desirable to increase the efficiency of power transfer.